Shift various things from south_africa to spinner.

All the things below appear to be general enough that they could be
defaults for the carousel from the spinner app rather than coming
from south_africa.

As the country_app appears before spinner in installed_apps, they
can be overridden by providing them in the country_app itself.
Whitespace changes
Replace featured person with carousel (NG)

For issue 1250, replace the featured person on the right hand side
of the home parge with a carousel like ZA.

Styling is obviously very basic.
Reorganise sass to share some carousel stuff.

Looks OKish for nigeria but I've not yet checked south_africa as
I don't have a dev site with a good enough database.
Add pombola.spinner to OPTIONAL_APPS in the new settings modules
Add some space under the carousel

Otherwise it touches the LATEST POLL heading
Make sure the carousel image doesn't overflow its container
Make the background of the Nigerian carousel "ShineYourEye blue"
NG: generate square thumbnail images for the carousel

This is requested by Paul Lenz, since apparently all the images that
will be used will in the carousel in are of square proportions.
Add "latest news" blog to home page of ShineYourEye
Improved design for the list of blog posts.
Tidy up the blog post styles.
initial attempt at getting homepage under control
better homepage typography on small screens
neater header
better breakpoint behaviour on homepage
better styling for blog listing page
better headline styling for blog posts themselves
fix poll border nesting bug
reposition nigeria homepage carousel arrows